Here is an unclean workaround for an observed segfault.
We need to find the root cause and fix it, because the
observed problem could arise in a different case where
we don't happen to use such a workaround.

In 'census_view.cpp':

warning()
<< "Line #" << current_line << ": "
...
<< LMI_FLUSH
;
// TODO ?? It would be better to use fatal_error() instead of
// warning() followed by fatal_error() with a short string, but
// apparently that can segfault with very long strings. Is there
// a limit on exception size that should be tested here?
fatal_error() << "Invalid input." << LMI_FLUSH;

I never documented a failing testcase; we should try to
establish one using the applicable portion of the original
code--see:

I believe that ultimately wxSafeShowMessage() should have
been called, but it would seem strange indeed for that
function to segfault, so we really need to nail down a
reproducible testcase. It seems conceivable that the
original code

throw std::range_error(error.str());

caused the segfault before it had a chance to be caught
and fed to wxSafeShowMessage(), though again that would
seem most strange.